package com.live.stamp.base.messageconverter;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializerProvider;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;

import java.io.IOException;

/**
 *
 * json null 转换成“”
 *
 * Created by wdcao on 2017/11/22.
 */
@Configuration
public class JacksonConfig {

    @Bean
    @Primary
    @ConditionalOnMissingBean(ObjectMapper.class)
    public ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {

        ObjectMapper objectMapper = builder.createXmlMapper(false).build();
        // 为mapper注册一个带有SerializerModifier的Factory，此modifier主要做的事情为：当序列化类型为date,int时，当值为空时，序列化成0
        objectMapper.setSerializerFactory(objectMapper.getSerializerFactory().withSerializerModifier(new MyBeanSerializerModifier()));
        objectMapper.getSerializerProvider().getDefaultNullKeySerializer();
        objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>() {

            @Override
            public void serialize(Object o, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException, JsonProcessingException {
                jsonGenerator.writeString("");
            }
        });

        return objectMapper;
    }
}
